The Steller jay is the most commonly seen and nests in the high forest habitat. Photo by Bob Walker
By ROBERT DRYJA
Los Alamos County can be divided into various kinds of ecological habitats. One approach has divided the county into habitats based on the predominant kinds of tree growing in them.
Different species of birds in turn prefer a particular kind of habitat for breeding. We had previously considered birds that breed in the juniper/pinon habitat toward the Rio Grande and other birds that prefer the ponderosa forest habitat further up the mountains. We also had considered birds that are generalists, breeding in all the habitats throughout the county.
Three general patterns have occurred in these previously considered habitats. The number of birds seen annually has increased in recent years when all the species in a habitat are considered together.
However, there are two different trends occurring within the overall group. (1) The most common species in a habitat have tended to become even more common over the years. (2) The less common species in turn have tended to remain the same or have decreased in numbers.
A third pattern also occurs. A reversal occurs from approximately 2000 to 2012. The less common species become more common while the most common species decrease in number. This period is between the two major forest fires and when draughts are occurring. The most common species then start to increase numbers after this time period ends. The combined impact of fires and drought changed habitats to favor some species while becoming less favorable for others.
These patterns continue when the high forest habitat is considered. Chart A shows that all the species together had annual counts of about 50 to 100 birds from 1989 to 2008. The number then increases to a peak 450 just after the forest fire in 2011. The annual count decreases thereafter and has remained in the 150 to 375 range since 2012.
The bird species of the high forest can be divided into two sub-groups. These are the seven most commonly and the seven least commonly seen species. The most commonly seen species are the source of the annual increase after 2008 when a particularly dramatic increase occurs. The trend line in Chart B looks very similar to the trend line in Chart A. Approximately 50 are seen annually before 2010 but then increases to about 150 to 350 thereafter. The most commonly seen species become even more common in effect.
The seven least commonly seen species indeed are rarely seen. Typically, only 3 to 5 are seen annually.
The forest fire in 2011 may have contributed to a decrease so that none or only 2 are seen annually for the three years after the fire. There is an increase to 11 seen in 2015 but the count decreases once again to be similar to prior years.
The Steller jay represents the extremes among the fourteen species. On the one hand it is rarely seen from 1989 to 2009. It then becomes the most commonly seen. Of the 459 birds seen in 2012, 341 are Steller jays.
The Mountain chickadee is among the three most commonly seen. Photo by Bob Walker
The Pine siskin also is a member of the three most commonly species that breed in the high forest habitat. Photo by Bob Walker
The Townsend’s solitaire is among the least commonly seen for high mountain forest habitat. It has been seen only 27 times in the past thirty years while the Steller jab has been seen 1,465 times. Photo by Bob Walker